Watch crown for waterproof watches



June 5, 1945. I C GREENBERG 2,377,625

WATCH CROWN FOR WATERPROOF WATCHES Filed Aug. 19, 1943 Chmia; B.Graznberg INVENTOR ATTORNEY Patented June 5, 1945 WATCH CROWN FORWATERPROO WATCHES Charles B. Greenberg, New York, N. Y.

Application August 19, 1943, Serial No. 499,239

3 Claims.

My invention relates to watch crowns and in more detail to waterproofcrowns of a type suitable for use with watch cases formed with a winding stem enclosing tube.

As waterproof watch crowns are subjected t considerable wear and hardusage due to the winding and setting of the watch, there is a tendencyfor the contact parts of the crown and the tube of the watch case tobecome separated with the result that the crown no longer seals the tubeopening and so loses its waterproof character. In addition, due to thesmall and delicate parts used in forming the present waterproof crownthere is little excess material to take up shock and resist wear withthe result that the crown cannot bear long, rough usage.

The purpose of my invention is to form a waterproof crown in which thesealing elements adjacent and subject to wear against the tube of thecase are of a substantial size and thickness to withstand the frequentsettings and windings of the watch. Another purpose is to form my crownwith two separate, individual closure elements which act independentlyand as successive bars to prevent any leakage of water, moisture or dustinto the case through the tube opening. A third purpose is to roduce awaterproof crown of minimum number of simple parts which can be quicklyand inexpensively assembled. A fourth object is to provide a strong,simple and wear resisting waterproof crown.

I accomplish these and many other objects by providing a cup shapedwatch crown with a rubber insert resting on the base and fitting snuglyagainst the inner sides and stem of the crown and insert above therubber washer a second rubber washer partially encased in a flangedtube, the tube fitting snugly against the inner sides of the crown withthe flange extending inwardly at the outer end of the tube, the secondwasher'provided with an annular opening at its center to fit snuglyagainst the tube of the watch case.

In the drawing, Figure 1 is a plan view looking into my cup shapedwaterproof watch crown and Figure 2 is a side view partly in sectionshowing the crown and its inside structure. In the drawing and in thespecifications corresponding numerals indicate the same elements. In thedrawing my cup shaped crown I is formed with the frame 2 and providedwith the circular side extending wall 3, base 4 and the internallythreaded post or stem 5 positioned in the center of the base.

An annular ring washer 6 is provided inside the crown frame and restingon the base 2. This washer fits snugly against the sides 3 and the post5. A flanged tube 1 is positioned by a force fit in the crown openingand presses on the washer 6. The tube at its outer end is provided withthe inward extending flange 8. A secondary or bushing washer 9 isprovided which rests inside the tube between the flange and the washer6. This bushing has an annular opening of the proper size to provide aclose fit with the tube (not shown) of the watch case. The watch casetube, when inserted, rests with its sides against the inner sides of thebushing and with its end against the face of the washer 6, thus there isprovided a double insulation for the tube opening. The washer 6 andbushing 9 are preferably made of rubber, vinylite or the like althoughany other material or composition which has sufficient resilience can beused.

The crown is assembled by inserting into the crown opening the washer 6and then adding the bushing 9 and tube 1 previously assembled. The forcefit provides a tight closure about the outer edges of the crown opening,and at the same time simplifies assemblage.

The construction of the crown may be varied by changing the flanged tubeinto an annular washer and increasing the diameter of the Washer 9 sothat it will rest against the crown frame. For this variation to holdtogether by a simple force fit the closure washer must be of asubstantial thickness to provide a suflicient bearing surface againstthe crown frame. This increase in thickness in the closure washerresults in a decrease in the depth of the resilient elements and so mayproduce a less efllcient crown.

Although I have onlyshown my waterproof crown in its main form, severalvariations in addition to the one described are possible withoutdeparting from the spirit and scope of the ideas conveyed in the drawingand descriptions, and so I desire to cover all modifications, forms andembodiments of my invention coming within the scope and language of anyand all claims.

I claim:

1. A watch crown for use with a watch case provided with a tube, formedwith a cup shaped opening therein, a winding post extending in theopening, a resilient washer resting in the opening and fitting againstthe cup sides and post, a flanged tube in the opening and resting on thewasher, the flange extending inwardly thereof, an annular ring resilientwasher extending between and resting against both the flange and thefirst washer, the resilient elements being held tosether and in thecrown frame by the tight fit of the tube in the cup opening, and theannular opening of the second washer being of such a size as to t snuglyagainst the sides of the watch case tube. 2. A watch crown for use witha watch case provided with a tube, formed with a cup shaped openingtherein, a winding post extending in the opening, a resilient washerresting in the openin and fitting against the cup sides and post, a tubewedged in the opening and resting on the washer,

said tube having an inward extending, flange, a 1 resilient? bushingextending between andresting against both the flange and the firstwasher and being held in position by the flange, and the internaldiameter of the bushing being-ofapmper. size to provide a close fit withthe sides of the 1;);

watch case tube.

3. A watch crown for use with a watch case provided with a tube, thecrown formed with a cup shaped opening therein, a winding post extendingin the opening, a resilient washer restin in the opening and fittingsnugly against the cup sides and post, a. tube wedged in the opening andsaid tube having an inward extending flange, a resilient bushingextending between and resting against both the flange and the firstwasher and boing held; in position by the flange, and the internaidiameter of the bushing being of a proper size to provide a close fitwith the sides of the watch case tube.

CHARLES E. GREENBERG.

